'use strict';
function choose_no_repeat(collect,num1){
  for(let num2 of collect){
    if(num2===num1){
      return false;
    }
  }
  return true;
}
function get_union(collection_a, collection_b) {
  let result=collection_a;
  for(let num of collection_b){
    if(choose_no_repeat(collection_a,num)){
      result.push(num);
    }
  }
  console.log(result);
  return result;
}

module.exports = get_union;
get_union([10, 27, 28, 19, 5],[5, 78, 28, 19, 23]);

